Infra-red-ray generator



Oct. 16, 1928. "1,688,124

H. P. M LAGAN INFRA-RED RAY GENERATOR Filed Jan. 192"! 2 Sheets-Sheet l v V INVENTOR. HECTOR P MAcA/IGA/v.

BWMMI (3. @144 ATTORNEY.

H. P. MacLAGAN INFRA-BED RAY GENERATOR Oct. 16, 1928'. 1,688,124

Fil Jan. 1927 2 Sheets-Sheet 2 i H I II II a a 2 INVENTOR. HEGTOE F? NACLAGAN.

A TTORNEY.

Patented 16, 1928.

UNITED STATES 1,688,124 PATENT, OFFICE.

" micron-r. IAcLAGAN, or on: max, rumors, AssIoNon ro morn-roan nLnc-rmcAn conronArron, or CHICAGO, rumors, A conroRArrou or DELAWARE.

INFRA-BED-BAY eEN'En ron.

' Application filed January 8,1927. Serial No. 158,574. I

My invention relates to an improved construction of infrared-ray generator for therapeutic purposes. In connection with the production of infrared rays for therapeutic 5 purposes, where the rays have been produced by electrically heated elements, difficulty has been experienced in the past in producing an element of considerable exposed area that would be uniformly heated over its entire l0 surface, and mounting the element in such a manner that the rays emanating from the exposed surface would be projected with maxi-' mum efficiency and effect towards thcsubject being treated. This diihculty has been experienced particularly where electrically heated resistance wires have been employed, on account of the necessity of mounting the resistance wires on a suitable insulating medium, which has usually had the efi'ect of producing a marked difference in the degree of heat between the wire and the insulating material, as a result of which to produce any considerable quantity of infra-red rays by the elementas awhole, the resistance wire has necessarily been heated to a-much higher degree than required to send off the desiredinfrat-red rays from the, resistance wire itself, to the end that the insulating material might be sufiiciently heated to become efiectiv-e in shorter wave lengthvthan the desired infraredrays have been deliveredv from the eleencein the rays given ofi'by the generatorcontainina the element, have not only reduced the eificiency of operation of thegenerator but in many cases, by the action of the light waves i of shorter wave length, have produced nude 40 perienced with electrically heated elements in the past, has been that where electrically heated resistance wire is'used as the-source of infra-red rays, it has been" difficult, if not impossible, to select the heatedmaterial from the standpoint. of the mostefl'ective production-of infra-red rays, for the reason that metalor ametallic alloy has generally been found to be the onlything thatlwould efi'ec- -.tively respond to the flow of electric'current to :produce the desired heat and'such metallic I surfaces, particularly when heated,.are not in at classification ofideal black bodies, which sending off such'rays at least toan appreciable extent. "As a result, light rays ofmuch ment in considerable quantity and their pres-.

sirable results where only infra-red ray treatments-were desired. A further difficult'y ex-. would beconsidered rmissible with the resistance units r'eferre to. T8 secure the ends described, I deeply embed the resistance wire 'terial, to the end that the heat develo have been found to most effectively produce infra-red rays if they could be suitably heated.

By my invention, I construct an element for the production of infra-red rays .in such a manner that although it is heated electrically by the .fiow of current through .a resistance wire, and the wire employed may be selected from the standpoint of most eflicient electrical action, I avoid the concentration of the heated areas, and I further avoid the efiect of direct projection ofthe light rays from the wire itself, by mounting the resistance wire ina deeply grdoved insulating support and filling the groove outside of the wire with insulating vmaterial selected primarily to present a radi- The heating element ofv my invention distinguishes sharply from resistance units heretofore employed having embedded wires, in that 30 in said resistance units'the purpose is to protect the resistance wire against disintegration and at the same time to place the wire asnear the surface of the unit as possible, sothat the heat developed may be radiated as rapidly as possible with the wire protected from contact with the air; in constructing my heating element on the other hand,'it is desired to-produce a highly heated condition of the insulating support and radiation of the heat in the same manner that it is effected in an embedded resistance unit, would defeat the purpose of i the present invention, and furthermore the resista'nce wire in my heating unit is heated purposely to a much hi her de ee than 9 in suitable grooves in the insulatin supportand then place in the grooves outside of the .10 wire a substantial thickness of insulating ma: 7

d by the resistance wire cannot be freely an readily communicated through the insulating material covering it, direct v to the atmosphere, but that on the other handvthe only manner by which the heat can be radiated is to heat the .enti re insulating support and insulatii g mk 'I i terial in the grooves to such a degree that the entire exposed surface is a dull red color, particularly adapted to give off infra-red rays.

grooves being preferably about twice the out-' side diameter of the wire helices and the amount of material of the insulating support remaining between the helical grooves eing as small as it can consistently be made from mechanical considerations.

My invention further consists in mounting a plurality of elements of the kind referred to 1n a convenient holder, located in a reflector providedwithan insulating handle and connecting devices by which the generator as. a whole may be convenientlyconnected with a source of current su ply. The holder for the elements is referab y constructed so that any one of the e ements may be removed from the holder without disturbing the other elements, at the same time permitting the generator to be used with the remaining elements as though the one element had not been removed, which is of considerable advantage where for any reason it is necessary to repair or replace one of the heating elements.

My invention will best be understood by reference to the accompanying drawings showing a preferred embodiment thereof in which Fig. 1 shows my generator in assembled condition in front elevation,

Fig. 2 shows my assembled generator in I side elevation,

Fig. 3 is a lon 'tudinal sectional view throu h the assem led generator to an enlarge1 scale, taken along the line 3-3 in Fig. 1 an Fig. 4 is a longitudinal central sectional view to a further enlarged scale through one of the heating elements.

Similar numerals refer to similar parts throughout the several views. v i

As shown in Figs: '1' and 2, my generator consists of a handle or support 10 :of insulating material, for example lava or porcelain on one-end of which a reflector 11 is mounted and on the other end of which a screw plug 12is secured for connection with a suitable source'of current. Within the reflector 11',

asshown in Fig. 1, two supporting arms 13 and 14 are secured and the outer ends of these arms are provided with clamping screws 15 and 16 engaging opposite sides of a first mounting ring 1 The ring 17 which may .ducting ring 22.

be of any suitable conducting material is provided with a plurality of slots 18 which are preferably equidistant to receive the rods 19 extending outwardly from the'heating elements 20. The elements 20 are provided with inwardly extendin rods 21 engaging suit- .able slots 22 in an lnner supporting and con- The rods 19 and 21 are threaded at their outer ends to receive suitable thumb nuts by which the heating elements 20 may be clamped in the position indicated. The ring 22 is electrically connected with the arm 14 by a rod 23, which rod is insulated from the ring 17, the arm 14 being also insulated from the ring 17 while the arm 13 is electrically connected with said rin Each of the heating elements 20 is preferably constructed asshown in Fig. 4 and consists of a core of insulating material in which a helical groove 20* is'formed of a widthto readily receive the resistance wire 24 wound in helical form. The groove 20" is preferably about twice as'deep as thehelically wound wire 24 and the part of the groove outside of the wire 24, after it is placed in the groove, is filled with insulating material 25, preferably in paste form. The material of the insulating core is preferably porcelain or lava and the material of the insulating compound 25- is preferably similar, so that the core and insulating compound may be adapted to withstand a high degree of heat. The supporting rods 19 and 21 extend part way "111110 the core of the heating element as indicated, but are sufficiently separated so that they are electrically insulated from each other. The ends of the resistance wire 25 are continued through the ends of the core and are electrically connected with the rods 19 and 21 as indicated at 25' and 25" respectively, preferably by welding, to maintain goodelectrica-l connection therewith notwithstanding the repeated heating and cooling of the element. I 'find that lava provides a highly efiicient'surface for the radiation of in a-red rays when the material is sufficiently heated and I therefore prefer to use lava as the core material of the heating elements and I prefer to employ filling material 25 which consists preferably .of lava in ground or owder condition, or the constituent parts of aim, to the end that when the filling material 25 is dry and baked in place by the heating of the resistance wire, it will have substantially the same radiating characteristics as the material of the core. With this construction it will be observed, a substantial amount of insulating material is present in the groove outside of the heating wire, and onaccount of this material having substantially the same heat conducting characteristics as the material of the core, and the wall of the core between the convolutions of the grooves being relatively thin, the entire outer surface of the coreand filling material 'the. heatingwire and as a resultfin manner for exam le b screws thus each of the elements 20 is efl ective in directing rays outwardlyfro'm substantially half of its surface,while' the'rays projected from the other half of its surface are'directed outwardly by the reflector 11 and in this man- /ner substantially all of 'the radiating effect of the heating elements is utilized. As indicated in Fig. 3, the arms 13 and 14 are'se cured at their inner, ends in any convenient to a plug of refractory insulating material 26 contained inthe reflector 11 and secured to the insulating support 10 by threaded conducting rods 27 and 28, which extend entirely through the support 10 and connect with the twoftermi nals 12 and 12 respectively of the connecting'plug- 12. At its inner-end the rod 27 iselectrically connected with the arm 13 and the inner end of the rod-28 is electrically connected with the arm 14, so and 14 become parts of the supply circuit for supplying: current to the heating elements 20. The insulation of thearm 14 from the that the arms 13 .ring 17 as well as\the electrical connection between the rod 23 and the ring 22 and the arm let is indicated in Fig. 3, which results in the rings 17 and 22 forming the electrical supply terminals for the several heating elements '20. From this struction of the rings above described, it will appear that the insertion of any one of the heating elements=20 inthe'cdrresponding slots in the rings .17 and 22 and the clamping of the elements in place by the corresponding thumb nuts indicated, 'at the same time affor'ds the heating element mechanical sup-' ing the generator port and electrical connection with the circuit of thegenerator, and that the several heating elements are connected in parallel relation between the supply'terminals'of the 'circuit. Each "one ofthe heating elements 20 therefore operates independently. of the others toproduce its intended heating and radiatingtefleet, and when for v any reason, forexample for substitution or repair, it is necessary .to remove one ofthei'heating ;ele- 'ments 20, it may ingits thumb nuts and removing the element the supporting rings, leav readily be done by releasfromithe slots in p operative as to the remaining heating elements 'so that if any delay, is

experienced in repairing or substituting the removed element, the generateras a whole is- ;not patent of COmmISSiOII.

-red U-shaped b orm manner, when the degree of heatingconnections at opposite'ends of saidel elements,

.mal to the axis of said and the slotted con 1 of said bands comprising the connections at opposite ends of It will be noted'that the arms 13 and '14 are provided adjacent-their inner ends with eflids 13", 14' respectively, and that they are bent inwardly at their outer ends;

this construction affords a resilient support for the heating elements to protect them from jar and shock and the inturned outer ends of the arms tend to retain the heating element assemblyin place against accidental v dislodgment when it is desired to remove the assembled heating element as 'a whole from the generator. I

While I haveshown my invention in the particular embodiment above described, it

. will be understood that I do not limit myself to this exact construction-as I may employ" equivalents known to the art at the time of the filing of this application without departing from the scope of the appended claims. What I claim is: 1 g I 1. In an infra-red ray generator, the combination of a plurality of heating elements arranged substantially in the same plane normal to the axis of said generaton'electricalf ents, and electrical terminal bands of metal, each connected with one terminal of each of said one of said bands comprising the mechanical support for said elements. 2. In aninfra-red ray generator, the combination of a plurality of heating elements arranged substantially in the same plane norgenerator, electrical connections at opposite ends of said elements, electrical terminal bands of metal, each connected with one terminal of each of said elements, and arms'supporting said bands.

3. In an infra-red ray generator, the combination of a vplurality of heating elementsarranged substantially in the same plane normal to the axis of said generator. electrical electrical terminal bands. of metal, each con-- nected with one terminal of each of said elements. andarms supporting said bands, one

mechanica'l'support for said element's.

' connections at opposite ends of said elements,

' 4-. In an infra-red ray generator, the'com- I .bination ofa plurality of heating elements arranged substantially in the same plane normal to the axis of said generator, electrical said elements, electrical terminal bands of metal. each conlnected with one terminal of each of said elements, a reflector, and an insulating sup.-

.port for said "reflector and said bands holdlng saidelements substantially in the plane of the open end of said reflector.

bination of a plurality of heating elements arranged substantially in the same plane,

5. In an infra red ray generator, thecom- I normal to the axis of said generator, electrical cdnnections at opposite ends of said elements, electrical terminal bands of metal.

each connected with one terminal of each of substantially in the plane of said 'elements,'armssupporting said bands, a

reflector, and an insulating support for said reflector and said arms holding said elements the open end of said reflector.

6. In an infra-red ray generator, the combination of a plurality of heating elements arranged substantially in the same planecomprising screws and nuts readily separable from said bands as desired.

7. In an infra-red ray generator, the combination of two spaced and concentric mounting rings of metal, heating elements'disposed between said rin connected therewlth', supporting arms connected with said rings, and an insulating support connected with saidarms 8. In an infra-red ray generator, the combination of two spaced and concentric mountmg rings of metal, heating elements disposed between said .rin s and having their -ends connected therewith, supporting arms connected with said rings, and in insulatingsup- I mounted on said support ',substantially in the plane of said rings.

port connected'with said arms, the was of said insulating support being substantially normal tothe plane of said rings.

9. In an infra-red ray generator, the combination of two spaced and concentric mounting rings of metahheatmg elements disposed between said rings and having their ends connected therewith, supporting arms connected with said rings, an insulating support connected with said arms, and a reflector with its open end 10. In an infra-red ray generator, the combination of two spaced and concentric mountmg rings of metal, heating elements disposed between said rings and having their'ends connected therewith, supporting arms connected with said rings, and an insulating support connected with said arms, said heating elements being cylindrical with their axes radially disposed between said rings.

11. In an infra-red ray generator, the com bination of itwo spaced and concentric-mounting rings of'metal, heating elements disposed between said rings and having their ends connectedv therewith, supporting arms connected with. said rings, an insulating support connected with said arms, said heating elements being cylindrical with their. axes radially disposed between said rings, and a reflector mounted on said support with its open end substantially in the plane of-said I f I 12. bination of two spaced an ing rings of metal, heating elements disposed between said rings and having their ends and having their ends connected therewith, :nected with said rmgs, -s

4 rings. In. an infra-red raygeneratonthe comconcentric, mountconnected therewith, supporting arms connected with said rings, and an insulating support connected with said arms, the connections between said heating elements'and said rings comprising screws and nuts readily separable to permit insertion and removal of said elements as desired. r

13. In -an infra-red ray generator, the combinationof t'wo'spaced and concentric mounting rings of metal, heating elements disposed between said rings and having their ends connected therewith, supporting arms, connected with said rings, and an insulating support connected with said arms, the connections between said heating elements. an said rings comprisingscrews and nuts readily separable to permit insertion and removal of said elements open ended slots for receiving said screws to facilitate the insertion and removal of said elements.

14:. In an infra-red ray enerator, the comas desired, said rings having bination of two spaced and concentric mountheating elements disposed and having their ends supporting arms conand an insulating supportconnectedwit aid arms-said rings being insulated from each other and comprising the electrical connections for supplying rings of metal, between saidrings 'ing current to said heating elements.

15. In an infrared ray generator, the combination of two spaced an concentric mounting rings of metal,'\ heat1ng elements disposed between said rings and having their ends connected therewith, supporting arms connected with said rings, and an insulating. support connected with said arms, said rings be ng insulated from each other and compris ng the electrical connections for supplying cur-.

rent to said heating elements, and each of said arms being electrically connected with one of said rings and insulated from the other of said rings.

16. In an infra-red ray generator, the combination of two spaced and concentric mounting rings of metal, heating elements disposed between said rings and having their ends connected therewith, supporting arms connected with said rings, an insulating support connected withsaid arms, said rings being insulated from each other and comprising the electrical connections for su plying current to said heating elements, 0th of said arms being mechanically connected with the outer one of said rings, ,one of said arms being electrically connectedwith and the other of said arms being insulated from saidouter- 17. In aninfra-r ed ray ing rings-of metal, heating elements disposed between said rings and havingtheirends generator, the com- I bination of two spaced and concentric mountconnected therewith, sup orting arms coni nected with said rings, an an insulating support connected with said arms, said heating elements each com rising a cylindrical core of refractory insulating material having a helical groove in its outer surface, a helically wound resistance wire wound'in said groove,

' said grooves being substantially deeper than ing rings of metal, heating elements disposed between said rings and having their ends connected therewith, supporting arms connected with said rings, and an insulating support connected with said arms, said heating elements each comprising a cylindrical core of refractory insulating material having a helical groove in its outer surface, a helically support connected with said arms,

connection between said arm an wound resistance Wire wound in said roove, said groove being deeper than the outside d1- ameter of said helically wound .wire by an amount substantially edual to'the separation of adjacent convolutions of said groove, and refractory insulating material filling said grooveoutside of said wire. I

19'; In 'aninfra-red ray generator, the combination of two spaced and concentric mounting rings of metal, heatin relements disposed between said rings and aving their ends connected therewith, 'supporting arms 'con nectedv with said rings, and an insulating said arms having bends in them affording a-resilient support for said .rin

20. In aminfra-re ray generator, the com.- bination of two spaced and concentric mounting rings of metal, heating elements disposed between said rings and having their ends connected therewith, supporting arms connected with said rings, an insulating support connected with ,said arms, a screw and nut connection between one of said arms'and the outer one of said rings insurin electrical said ring, and a threaded .rod electrically connected with the other of said arms and extending to and making electrical connection with the inner one of said rings, said threaded rod bein mechanically connectedwith but insu-.. lated from the outer one of said rings. 1

i 21. In an infrared ray enerator, the com bination of two spaced am? concentric mounting rings of metaL'heating elements disposed F between said rings a'nd Having their ends connectedtherewith, supporting arms connected'with said rings, an msulating support connected with said arms, a screw and nut connection between' one of said arms and the outer one of said rings' electrical connection between said arm an said ring, and a threaded. rod electrically connected with the other of said arms and extending to an'd'making electrical connection with the mner one of said rings, said threaded rod being mechanically connected with but insulated from the outer one of said rings, each of said heating elements comprlsing a core of insulating material and a resistance wire having its ends connected respectively with said rlngs.

'22, In aninfra-red ray generator, the combination of two spaced and concentric mounting rings of metal, heating elements disposed between said rings and having their ends connected therewith, supporting arms. connected with said rings, an insulating support connected with said arms, said insulating support being elongated to form a handle for said generator, a two part electrical plug on the end of said support remote from'said A arms, and rods extending through said support electrically connecting said arms respectively with the parts ofsaid plug.

23. A. heating element for an infra-red ray generator comprising a core of refractory 'insu ating material havlng a groove in its outer surface, a resistance wire in 'said grooye, and refractory insulating material filling said groove outside of said wire, said filling material having a depth distributing the heating effect of said wire throu h the outer portion of said core and throng said filling material to beat them substantially uniformly to a dull red heat. i

24: A heating element for an infra-red ray I generator comprising a core of refractory in of said core and through said filling material to heat them substantially uniformly to a dull red heat, said groove being helical and'extending from endto end of said core, and said .wire being in helicallywound condition before being wound in said groove.

25. A heating element for an infra-red ray generatorcomprisinga core of refractory insulating material having a groove in its. outer surface, a resistance wire in' said groove, and refractory insulating material filling. said groove outside of said wire, said fillin rial having a depth distributing .the heating effect of said .wire through the outer portion of saidcore and through said filling material to heat them substantially uniforml to a dull red heat, said groove being helical and extending from end to. end of said core, and said wire being in helically wound condition 1 before being wound in said ve, said groove bein wider than the thickness of the portion of t e core separating adjacent oonvolutions of said groove; 7

26. 'A heating element for an infra-red ray matei eneratorcomprising a core of refractory insulating material having a groove in its outer surface, a resistance wire in said groove, refractory insulating material filling said groove outside of said wire, said filling matefactory insulating material filling said groove outside of said wire, said filling material having a depth distributing the heating effect of said .wire through the outer portion of said core and throu h said filling material to heat them substantially uniformly to a dull red heat, and screws projecting from the 'ends of said core for mounting purposes, said screws being insulated from eachother and connected with the ends of said wire.

28. Aheating element for an infra-red ray generator com rising a core of refractory insulating material having a groove in its'outer surface, a resistance wire in said groove, refractory insulating material filling said groove outside of said'wire, said filling material having a depth distributing the heating effect of said wire throu h the outer portion of said core and throng said filling material to heat them substantially uniformly to a dull red heat, said groove being helical and extending from end to .end of said core, and said wire being in helically wound condition before being wound in said groove, and screws pro ecting from the ends of said core for I mountin vpurposes.

29. A eating element for an infra-red ray generator comprising a core of refractory insulating material having a groove in its outer surface, a resistance wire in said groove, refractory insulating material filling said groove outside of said wire, said fillin material having a depth distributing the mating efiect of said wire-through the outer portion of said core and through said filling material to heat them substantially uniform- 1y t adull red heat, said groove being helical and extending from end'to end of'said core, and said wire being in'helically wound condition before being woun-d in said groove, and screws projecting from 'the ends of said core for mounting purposes,said screws being insulated from each other and connectedwith the ends of said wire.

In witness whereof, I hereunto subscribe my name this 23rd day of December, A. D. 1926. w e

HECTOR P j MAoLAGAN. 

